Plastic stretch films (also referred to herein as plastic webs) are typically manufactured by either a cast or blown-film high-speed extrusion process, which initially produces the film as a continuous, wide sheet. The films themselves are typically used as an industrial shipping material used to wrap and thereby hold merchandise on a pallet for shipment. The stretch wrap is applied to a load on a pallet either by a stretch wrap machine, in which case the resulting material is referred to as “machine wrap,” or by an individual operator, in which the material is referred to as “hand wrap.” Currently, stretch film is manufactured at too great a width for either machine wrap or hand wrap applications, so the sheet is typically reduced to standard widths prior to use. Depending on the particular manufacturing facility, the as-manufactured sheet will either be slit to the narrower width after manufacture but prior to initial winding, or wound into a full width mill roll and then slit and rewound out of line with the high-speed extrusion operation.
Historically, the “hand wrap” products were wound on the same diameter cores as the “machine wrap” products. Although core usage has always been a necessary but additional expense item for the manufacturer, a significant change is now taking place primarily in the hand wrap market; smaller, thinner, and, optimally, no cores being desirable to reduce costs and to reduce waste. With currently available winding machinery, it is not practical to make these smaller, thinner or coreless products at speeds that will accommodate winding in line with current extrusion processes, so producers are forced to wind large diameter mill rolls in line with the film extrusion process, and then slit and re-wind the film in an off-line operation. In many instances, the slitting is performed before the mill roll is wound and the rewind operation is performed without further slitting. The off-line operations increase the time and cost required to manufacture the film product sold to the end user. Additionally, to provide adequate separation between adjacent winding rolls, it is customary when slitting the film to make two adjacent parallel cuts, resulting in a narrow ribbon of material referred to as “bleed trim” that must be recycled.